Chain-grate stoker.



W. W. HOLLAND, i. R. CARRZNGER (it W. BACHELDUR.

CHAIN GRATE STOKER.

' APPLICATION FILED JAN. 12, 1913.

Patented June 11, 1918 I did" it i WILLIAM W: HOLLAND, 01F ALTON, AND 313$ R. CARRINGER AND WILLIAM EAGHELDOB, E WOODRIVER, ILLINOIS.

" GHAIN-GRATE sronnn messes specification of Letters Patent.

Patented dune llil, timid.

Application filed January 12, 1918. Serial Ito. 211,528.

To all whom it may concern son, State of Illinois, JAMES R. CARRINGER,

a resident of Woodriver, county of Madison,

State of Illinois, and WILLIAM Bnonnmon,

- a resident of Woodriver, county of Madison,

State of Illinois, all citizens of the United States of America, have invented certain new and useful Improvements in Chaim Grate Stokers, of which the following is a specification.

. In the operation of mechanical'stokers, particularly those of the chain grate type, the life of the apparatus is limited by the failure of the links and rods, due to these parts becoming cemented together by rust and other deposits.v This is more often than otherwise due to the Wetting of the fuel prior to feeding it to the furnace, the new fuel being in this type of apparatus fed on to the bare grate as it comes into position near the furnace'door and carried backward to the point of combustion. This gives the water a chance to run down on to the grate and as the coal often has mixed with it various soluble salts, these are deposited on the bars of the grate by evaporation of the water due to the temperature of the bars. Where the ate is intensely hot, a harder deposit may e formed by fusing of the salts. This I deposit forms on the various exposed surfaces of the grate but the fact of importance in the present case is that it forms.

on the transverse rods and in the apertures 4 in the links through which the rods pass and tends to cement these parts together, or, failing this, to reduce the size of the apertures and increase the diameters of the rods imparting to the structure a greater or less degree of rigidity) ln'all chain grates, there isnormally a slight relative motion or" thelinks and rods, i. 6., swinging of the links and rotation of the rods, which is sufiicient when the deposit has formed to break the links and twist the rods when this relative motion of the' parts is thus checked. The object of our invention is to provide means which in the ordinary operation of the structure will serve toream out the de posit and thus preventth'e harmful accumulation with the consequent cementing to gether of the parts and arrest of their relativemotion from cementation'or clogging.

articulation, e., where the relatively moving parts are in contact of necessity, results in a considerable increase in the life of the structure.

In the accompanying drawing, we have shown in Figure 1 an elevation of a grate rod constructed in accordance with the preferred form of our invention;

Fig. 2 shows a link with a transverse section of grate rod;

Figs. 3, 4c and 5 are cross-sections of modified forms of grate rod included within the broader scope of our invention.

Referring to the drawing b numerals, the structure may he considers to be of the general type, the invention being as much applicable toone type of chain grate stoker as another and of course capable of use with forced, natural or induced draft apparatus; The illustration includes links 7 having spaced apertures 8 through which the rods 9 pass; the latter may extend from side to side of the grate and. serve as the pins on which the links of the chain are pivoted to each other. Such rods have ordinarily been made round but the rod 9 illustrated in Figs.

vt- I 1 and 2 isa twisted rod of square material I and is of the kind used in reinforced con--' crete work. Such rods present helically disposed edges to the inner walls or surfaces of the apertures in the links. The links have a slight swinging or rotative motion on thecumulation of the deposits referred to, with consequent cementation and clogging, but it is sufiicient when such deposits prevent relative motion of the parts to cause the breaking of the links and twisting of the rods, and incidentally a considerable loss of power. The rod 9, provided as illustrated, with reaming or cutting edges and preferably.

flattened or otherwise reduced between or adjacent the cutting edges, has the edect of continually reaming out the deposit as formed, so that cementing of the parts or accumulation of'the deposit serving to limit their relative-motion is prevented. This result may be accomplished by any cutting or 55 The absence of this deposit at the points of reaming edge or corner 11 on therod ex- 11otending in the general direction of the length of the rod or even intersecting the transverse plane of the rod, as by use of a straight square red as shown in Fig. 3, a hexagonal red as shown in Fig. 5, or by a round rod having a single cutting edge as illustrated in Fig. 4. In the form shown in Fig. 1, the cutting edges are helical and serve to bore the material out as by means of an auger. These cutting edges are preferably arranged in the form of wright-handed helix on part of the rods and a left-handed helix 'on the remainder of the rods, the rods with the right and left handed helices being alternately arranged to prevent creeping of the grate to either side, and the right and lefthanded helices may be variously combined Within the scope of the invention to produce the same or an equivalent result. These rods are shown in cross-section in Fig. 2, the number of cutting edges on each being variable to meet the conditions presented. The length of the rods is immaterial; they may either be bolts or extend entirely across the grate and the cutting edges need extend only so far as they are eii'ective, not being necessarily continuous. The use of the pivotal rods, flattened and provided with cutting edges as shown, greatly reduces the frictional bearing surface and makes it possible to actuate the grate with a correspondingly reduced amount of power.

We have thus described specifically various embodiments of our invention in order that the nature and operation of the same may be clearly understood, so as to permit those skilled in the art to practice the invention. However, the specific terms herein are used descriptively rather than in their limiting sense and the scope of the invention is defined in the claims.

We claim- 1. In combination in a chain gratestoker, a link, cross-rods on which the link is pivoted, the link being apertured to receive the rods and the rods having projecting edges to ream the deposits from the apertures in the links.

2. In a chain grate, a. transverse grate rod or pivot provided with scraping means to remove the deposit from surfaces contacting with the rod. 3. In a stoking grate, a link and transverse rods to which the link is pivoted, the rods having spirally arranged cutting edges serving to engage the surfaces of the apertures and rea m out the deposit as formed, part of the rods having the cutting edges in the form of right-handed helices, and the remainder in the form of left-handed helices, the rods with the right and left-handed helices being alternately placed. I

4. In a chain grate having links joined by transverse pivot rods,the links having apertures cooperating With the rods to form bearings so that the rods and links have cooperating bearing surfaces, one of the cooperating bearing surfaces having scrapingedges to remove the deposit which forms between the rods and links.

Signed by us at Woodriver, 111., this 7th day of January, 1918.

WILLIAM W. HOLLAND. JAMES R. CARRINGER. WILLIAM BAGHELD'OR. Witnesses:

ELMER H. PAITNE. RAYMOND F. BUCK. 

